Lime Lake Final Results Portage County Lake Study University of Wisconsin-Stevens Point, Portage County Staff and Citizens March 31, 2005 What can you learn from this study? You can learn a wealth of valuable information about: Critical habitat that fish, wildlife, and plants depend on Water quality and quantity of your lake The current diagnosis of your lake good news and bad news What can you DO in your community? You can share this information with the other people who care about your lake and then plan together for the future. Develop consensus about the local goals and objectives for your lake. Identify available resources (people, expertise, time, funding). Explore and choose implementation tools to achieve your goals. Develop an action plan to achieve your lake goals. Implement your plan. Evaluate the results and then revise your goals and plans. 1
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Lime Lake ~ Location Lime Lake North of County Trunk D, southwest of Amherst, Town of Amherst Surface Area: 48 acres Maximum Depth: 29 feet Lake Volume: 804 acre-feet Water Flow Lime Lake is a groundwater seepage lake Water enters Lime Lake mostly from groundwater, with some runoff and precipitation Water exits the lake to groundwater 3
Lime Lake ~ Land Use in the Surface Watershed Surface Watershed: The land area where water runs off the surface of the land and drains toward the lake. Current Predominant Land Use Around the lake: forest, residential, and shrub cover In the watershed: nonirrigated cropland, residential, forest, shrub cover and permanent pasture Surface Watershed: 336 acres Lime Lake Rd 160 Surface Watershed Land Use Acres 140 120 100 80 60 40 20 0 Residential Transportaion Non-irrigated Cropland Permanent Pasture Confined Animal Farmstead Forested Coniferous Plantation Shrub Cover Water 1948 1968 1990 2002 Surface Watershed Land Use The dominant land uses in the surface watershed are non-irrigated cropland and forestland, both of which have declined slightly in recent years Residential use is increasing while all other uses have remained relatively constant 4
Lime Lake ~ Land Use in the Groundwater Shed Groundwater Shed: The land area where water soaks into the ground and travels underground to the lake. Town Line Rd Cty Hwy K Current Predominant Land Use Major land uses in the groundwater shed are nonirrigated cropland, residential, permanent pasture and forest Lime Lake Rd 300 Groundwater Shed Land Use Acres 250 200 150 100 50 0 Residential Transportation Non-Irrigated Crop Land Permanent Pasture Confined Animal Operations Forested Shrub Cover Water Bodies 1948 1968 1990 2002 Groundwater Shed Land Use Non-irrigated cropland has dominated the land use since 1948 Shrub Cover decreased substantially between 1948 and 1968 All other land uses have remained relatively constant noting the increase in residential land use 5
Lime Lake ~ Taking a closer look (Within 1,000 feet of the lake) 2 3 Noted Features 1000 Foot Buffer 1000 Foot Buffer 1 4 2000 Orthophoto Points of Interest 1. It appears as though the wetlands on the east side of the lake were mostly covered in 1938 2. The only farm that has been on the lake since 1938. 3. A road was here until the early 1960s, today there is little presence of it ever being there 4. This area was cropland in 1938, now it has become residential. 9-24-38 1938 Air Photo Image 6
Lime Lake ~ Taking a closer look (Within 1,000 feet of the lake) Changes from 1938 to 2000 1938 2000 # of Docks Impervious Surface (acres) Residential (acres) Cropland (acres) Forest (acres) Wetland (acres) 1 1 0.4 55 25 27 0 6 8 43 23 28 Percent Land Cover Within 1000 Foot Buffer 60% 50% 40% 30% 20% 1938 2000 Wetland Cropland Developed Forest Impermeable Surfaces 10% 0% 7
Lime Lake ~ Water Quality Total Phosphorus In more than 80% of Wisconsin s lakes phosphorus is the key nutrient affecting aquatic plant and algae growth. Once in a lake system phosphorus levels are difficult to reduce, so limiting phosphorus input is key. Phosphorus at levels above 30 parts per billion (ppb) can lead to nuisance aquatic plant growth and accelerate a lake s change from oligotrophic to eutrophic. Sources of phosphorus include septic systems, detergents, animal waste, farmland and storm sewer runoff, soil erosion, and fertilizers for lawns, gardens, and agriculture. Oligotrophic Lakes Common uses: Swimming Skiing Boating Vegetation of oligotrophic lakes: Very little vegetation Mesotrophic Lakes Common uses: Boating Fishing Vegetation of mesotrophic lakes: Increased vegetation Occasional algal blooms Eutrophic Lakes Common uses: Fishing Wildlife watching Vegetation of eutrophic lakes: Lots of aquatic plants Frequent algal blooms Winter fish kills can occur 8
Lime Lake ~ Water Quality Average Total Phosphorus Levels Concentration (ppb) 60 50 40 30 20 10 0 Eutrophic Mesotrophic Oligotrophic Lime Lake Historic Average 2002-03 Average Definitions for eutrophic, mesotrophic and oligotrophic are on the previous page. The graph to the left shows total phosphorus levels measured when the lake was well mixed (overturn). Phosphorus levels in Lime Lake in 2002-03 are lower than average historic levels, however, they are still high. Levels of phosphorus above 30 ppb are high enough to categorize a lake as eutrophic, making it subject to nuisance algae blooms and aquatic plant growth. Compared to similar lakes in the region, Lime Lake has a relatively high concentration of phosphorus that is high for a marl lake. Overturn: uniform temperature from top to bottom in the lake. Water Clarity Water clarity (Secchi disc depth) is an indicator of water quality. The two main components affecting water clarity are materials dissolved in the water and materials suspended in the water. Water clarity can indicate overall water quality, especially the amount of algae and suspended sediment present. Depth from surface (ft) 0 5 10 15 20 Lime Lake The water clarity in Lime Lake is considered fair. The average Secchi depth reading for similar lakes in the region is 8-10 feet; Lime Lake appears to have slightly reduced clarity during some months. The water clarity of Lime Lake during the 2002-03 growing season improved during most months compared with the historical growing season average. The months of May, August, and September showed the best water clarity and the month of July the poorest. These fluctuations throughout the summer are normal as algae populations and sedimentation increase and decrease. May June July August Sept. Historic Average Historic Maximum 2002/2003 Averages Historic Minimum 9
2002 Amphibian Distribution at Portage County Lakes This summary provides preliminary information on the amphibian species present and their distribution at the twenty-nine Portage County lakes. Surveys were conducted from April 2002 - August 2002, the typical breeding period of the frogs and salamanders found in the county. Twelve frog species have been documented in Wisconsin, nine of which currently inhabit Portage County: American toad, chorus frog, spring peeper, eastern gray treefrog, Cope s gray treefrog, green frog, pickerel frog, northern leopard frog, and wood frog. Historically, Blanchard s cricket frog inhabited Portage County but is believed to now exist only in southeastern Wisconsin. Of all species believed to inhabit Portage County, only the pickerel frog was not found during the spring and summer of 2002. The pickerel frog has been listed as a species of special concern in Wisconsin. No new species to Portage County were recorded in 2002. Seven salamander species have been documented in Wisconsin, all of which currently inhabit Portage County: blue-spotted salamander, spotted salamander, tiger salamander, central newt, mudpuppy, northern redback salamander and four-toed salamander. The four-toed salamander is listed as a species of special concern in Wisconsin. Large sections of continuous natural shoreline on lakes are ideal habitats for frog and salamander populations. Natural areas with large amounts of submergent, emergent and floating-leaf vegetation provide protection for amphibians. Many species also use the vegetation for attachment of eggs during the breeding season. Green frogs, bullfrogs, pickerel frogs and leopard frogs depend on the shoreline area throughout the year. In contrast, American toads, spring peepers, tree frogs, wood frogs and chorus frogs depend on the shoreline area in the spring for breeding and then move to other areas for the rest of the year. Undisturbed areas of shoreline that are also connected to large natural upland areas provide ideal habitat for many amphibian species because they lessen frogs exposure to predators. Many frog and salamander species migrate to the lakes in the spring to breed and spend the summer months foraging in the uplands. Many amphibian species will also over winter in the uplands. Chorus Frog Spring Peeper Eastern Gray Treefrog Northern Leopard Frog Wood Frog American Toad Green Frog Cope s Gray Treefrog Blue-spotted Salamander Northern Redback Salamander 10
Lime Lake ~ Frogs and Reptiles Lime Lake Frogs and Reptiles Number of frog species: 4 Frog species observed: spring peeper, gray treefrog, Cope s gray treefrog, green frog Location of primary habitat: east side of lake Key features of habitat: protected areas of marsh with large amounts of submergent, emergent and floating-leaf vegetation Map Key Red outlined areas = primary frog habitat Good News Large sections of natural shoreline Number of reptile species: 2 Reptile species observed: painted turtle, snapping turtle 11
Lime Lake ~ Shoreline Vegetation Frogs and toads depend on shoreline and aquatic vegetation for: attachment of eggs during the breeding season, shelter for adults throughout the spring and summer, food for larvae, habitat for prey, and slowing evaporation and moderating temperature fluctuations. Frogs are commonly found in areas with large amounts of tree cover, aquatic plants, leaves, and downed branches, characteristics typical of natural areas. Frogs are not frequently found in sandy areas or open water, characteristics typical of altered areas. Though amphibians use drier prairies and woodlands near lakes and wetlands, this study focused on areas reaching from 16 feet into the lake to 33 feet inland. Lime Lake Green Frog Habitat Excellent Poor 0% 2% Green frogs are used as an indicator for the health of aquatic life in Wisconsin lakes because they are abundant, live in many cover types, and remain along the edge of the lake throughout the spring and summer. While other amphibians may require more specific cover types, the green frog habitat is a useful indicator. Some cover types (as shown on map above) are better than others for green frogs. Specifically: Excellent green frog habitat = cover types 1 and 2 Adequate green frog habitat = cover types 3, 4 and 6 Poor green frog habitat = cover types 5, 7 and 8 Lakes with larger amounts of good green frog habitat will likely support more amphibians and more species of amphibians. Likewise, amphibians are more likely to be harmed or eliminated with increasing shoreland development. Adequate 98% Best Green Frog Habitat: Ebert Lake 33% excellent habitat + 67% adequate Worst Green Frog Habitat: Helen Lake 2% excellent habitat + 6% adequate + 92% poor 12
Lime Lake ~ Fish Lime Lake Fish Number of observed species: 12 Species observed to date: This chart represents all species detected, by decade, in Lime Lake since censusing began. Data before 2002 was collected by the Wisconsin DNR and 2002/2003 data was collected by UW-Stevens Point. X represents a decade when the species was detected and S represents a decade when the species was stocked. 1970's 1980's 2000's Bluegill X X X Bluegill/Pumpkinseed hybrid X Pumpkinseed X X X Green Sunfish X X Largemouth Bass X X X Black Crappie X X X Walleye X,S X Yellow Perch X X X Iowa Darter X Northern Pike X X X Yellow Bullhead X X White Sucker X X Golden Shiner X X Central Mudminnow X X 13
Substrate: Bottom substrate is mostly marl mixed with small amounts of sand. Deeper areas near the north and south shore appear to have been dredged, a sign of marl removal. In the absence of sand and gravel, largemouth bass and sunfish build nests on marl especially if they can excavate a depression to a coarser substrate such as woody debris. Vegetation: Extensive emergent beds of cattail ring the lake with an expanse of rush and sedge in slightly deeper water along the eastern shore. Water lilies provide excellent edge habitat in deeper water along the south and west shores. Extensive beds of pondweed and common milfoil provide deep water cover. There is little woody cover along the shoreline to provide permanent cover. 14
Lime Lake supports a warm water fishery. The fish population is dominated by bluegill, largemouth bass and yellow bullheads. The lake has had a long history of stocking largemouth bass, bluegill and yellow perch dating back to 1930. In 1976, walleye were stocked, but there has been no evidence of reproduction and the population has apparently disappeared. The lake was considered to have potential as a trout fishery in 1958, but the lake also has been subject to winterkill and would be a poor choice for trout stocking because of periodic low dissolved oxygen. Twelve species of fish were collected in Lime Lake in 2002-2003 compared to 13 from historical records. The only new species found not previously reported from this lake include the bluegill/pumpkinseed hybrid. Pure pumpkinseed parentals are still found in the lake unlike several other lakes where they have been lost through introgression with bluegill. Species lost or not documented include the walleye, which would only be sustained through stocking, and the Iowa darter, a small bottom dwelling fish that is best caught by seine, which could not be used because of the soft bottom. Decline in the population of black crappie has occurred since the last WDNR sampling in 1986 when it was the second most abundant sport fish after bluegill. None were collected during daytime electrofishing in 2003 and only one was collected in 2002. There were also a lot fewer northern pike collected in 2002-2003 compared to 1986, but that difference may be due to our less effective daytime electrofishing. A substantial number of largemouth bass less than 13 inches are present in the lake. Yellow perch were more common than in the other lakes sampled in the 2002-2003 study. There is also a large population of sizeable yellow bullheads. The abundance of bullheads along with the high number of mudminnows suggests the lake may have been subject to low dissolved oxygen and possibly periodic winterkill. 15
Lime Lake ~ Aquatic Plants Aquatic plant surveys were conducted in each lake. More detailed information is available in the final report. Aquatic Plant Survey Lime Lake has at least 51 species of aquatic and wetland macrophytes, including 50 species of vascular plants. This is slightly above average for Portage County Lakes. Lime Lake and adjacent wet shore areas support a fairly large number of species, but almost no species which are rare or indicative of relatively undisturbed conditions. Among the most notable features of Lime Lake are the thick accumulation of marl in places such as at the boat landing on the north shore, and the abundance of two species of water-meal (the smallest flowering plants in the world). The two aggressive alien cattails are fairly well-established in places on the shore. Eurasian milfoil and curlyleaf pondweed have not been found in the lake to date, but both could become very abundant if established. Invasive Exotic Aquatic Plants Invasive species displace native species, disrupt ecosystems, and affect citizen s livelihoods and quality of life. They hamper boating, swimming, fishing, and other water recreation, and take an economic toll on commercial, agricultural and aquatic resources. (Wisconsin DNR) Aquatic plants surveys revealed that some of the lakes in the study have invasive aquatic plants present. Eurasian milfoil (Myriophyllum spicatum) was present in Bear Lake Lake Emily Lake Joanis Jordan Pond McDill Pond Springville Pond Thomas Lake Curly leaf pondweed (Potomogetan crispis) was identified in Spring Lake Amherst Millpond Contact the Portage County Land Conservation Department for additional information. 16
Lime Lake ~ What can you do to help? A lake is a magnificent water resource. The quality of its water is a reflection of what happens on the land that surrounds it. Lake Users: Run boat engines efficiently. Observe no/low wake zones. Refuel away from water. Dispose of trash properly Remove all aquatic plants from boats and trailers. Project support provided by: Wisconsin DNR Lake Protection grants UW-Stevens Point Portage County Portage County Citizens S tudy Contacts: Portage County: Steven Bradley at 346-1334 Land Owners: Control soil erosion. Keep livestock out of lakes and streams. Control manure runoff. Carefully manage nutrients and pesticides. Learn to identify and look for invasive species. Home Owners: Leave natural vegetation buffers in place or replace them if they have been removed. Eliminate the use of fertilizer or use low/no phosphorus fertilizer. Eliminate or minimize use pesticides. Control soil erosion. Clean up after of pets. Learn to identify and look for invasive species. UW- Stevens Point: Nancy Turyk at 346-4155 17
Lime Lake ~ Primary Researchers Algae Dr. Bob Bell Aquatic Plants Dr. Robert Freckmann Birds Dr. Tim Ginnett Brad Bulin (Graduate Student) Fish Dr. Ron Crunkilton Land Use Coverages/Watersheds Steve Bradley (Portage County Conservationist) Planning Assistance Lynn Markham Mike Hansen Reptiles and Amphibians/Near Shore Habitat Dr. Erik Wild Rori Paloski (Graduate Student) Water Quality/Watersheds Becky Cook Dr. Paul McGinley Dr. Byron Shaw Dick Stephens Nancy Turyk Near Shore Summary Dr. Glenn Bowles Special thanks to UWSP undergraduate and graduate students and local citizens for their assistance! 18